Method and means for burnishing spherical seats



Feb. 25, 194.1. A. E. DRISSNER ETAL 3 ,8 3

METHOD AND MEANS FOR BURNISHING SPHERICAL SEATS Flled Jan. 7, 1959 5 Sheets-Sheet 1 INVENTORS,

Feb. 25, 1941. A E, DRISSNER ETAL ,843

METHOD AND.MEANS FOR BURNI SHING SPHERICAL SEATS Filed Jan. 7, 1939 3 Sheets-Sheet 3 INVENT OR.

fBecwowc Patented Feb. 25, 1941 UNITED STATES PATENT OFFICE METHOD AND MEANS FOR BURNISHIN G SPHERICAL SEATS Alfred E. Drissner and Robert Beacom,

Ohio, assignors to The National Acme Cleveland, Ohio, a corporation of Ohio Cleveland, Company,

Application January 7, 1939, Serial No. 249,670

Claims.

Heretofore, in the manufacture of ball seats for tie rods andsimilar parts, theyhave been partly finished on semi-automatic or automatic machines and then the finishing thereof has been completed by a spherical grinding or coining secondary operationand, due to this secondary operation, the manufacturing costs increased because of such subsequent'handling, etc. In other words, it has been the practice to form the blanks from the stock bar or rod by the usual successive operations and then, after they are cut oil from the bar, the blanks were submitted to a subsequent operation to burnish them since no practical way has been known to burnish the blanks while still on the bar or rod and there were many objections to this method of procedure. Therefore, the present improvement has been developed as the result of many experiments. I

In the present instance, the burnishing tool is shown applied to the tool slide of a multiple spindle screw machine although it may be used with other machines.

In the drawings accompanying and forming a part of this specification, Fig. 1 is a side view of so much of a multiple spindle machine as is deemed necessary to show the present improvement. I I

Fig. 2 is a detail view of the burnishing tool and a sectional view of the blank.

Fig. 3 is a cross sectional view takenbn line 33 of Fig. 2.

, Fig. 4 is a side view of the mechanism shown in Fig. 1 with the mounting for the burnishing tool shown in section. I

Fig.5 is a cross-sectional view taken on line 5-5 of Fig. 4.

Figs. 6 to 11, inclusive, illustrate the several steps of forming the blank on the stock bar,

burnishing the same and cutting the burnished blank from its stock bar bythe use of suitable side and end working tools.

Similar characters of referenceindicate corresponding parts in the several views.

Before explaining in detail the present im-' provement and mode of operation thereof, 'we

desire to have it understood that the'invention is not limited tothe details-"of construction and arrangement of parts which are illustrated in the accompanying drawings since the invention 1 is capable of other embodiments, and that the phraseology which we employ is for the purpose of description and not of limitation.

When this improvement is used, for instance, with a multiple spindle machine, that machine usually consists of a series of rotary work spindles 2 carried by an indexible spindle carrier 3 and through these spindles the stock rods are fed in the usual manner and from these rods the blanks are'successively formed by the usual J side and end tools. I

The machine is also provided with a main sliding tool ca'rrier 4 to which the various end working tools are applied, such as drills, etc, and to which this improved burnishing tool is also applied. Side and top cross slides 5 and 6 carrying side and top tools for forming the blanks and-for cutting off the same atthe proper time in the usual way are also provided.

In Fig. 6, the-"blank is shown "partly formed by a side working tool and by an-end working tool; in Fig. 7, various side and "end working tools are utilized further to form the blank; in Fig. 8, the spherical seat of the blank is further formed by an end working tool while, in Fig. '9, this formation of the spherical seat is continued and, at the same'time, the cutting-off tool has commenced to sever the blank from the stock bar; Fig. 10 illustrates the burnishing operation while Fig. 11 illustrates the completion of the severing operation of the blank from its bar.

In the present improvement, the burnishing tool is carried by a suitable bracket or holder! having antifriction bearings 8 for supporting a freely rotatable shaft 9 having an enlarged socketed end'or head It! to which the shank H of the burnishing tool I2 is secured. This burnishing tool is forced into' the rough spherical seat 13 of the stock rod after that spherical seat has first been formed by the end working tools by the forward movement of the tool slide, wherebyit will freely rotate with the rotatable stock spindle, it being withdrawn from the spherical seat of the blank-as the tool slide moves away from the spindle carrier. Thus, the rotation of the stock spindle rotates the stock rod and the burnishing tool at the same speed as the work so that when thev burnishing tool is used on a multiple spindle machine, the burnishing of one piece of work proceeds as the other pieces are successively formed, drilled and bored, the spherical blank having a drilled opening therethrough as at [4.

The burnishing tool l2 which is formed at or attached to the end of the shank H, the shank being of somewhat smaller diameter than the Working surface of the tool, comprises what may be termed a truncated sphere rounded longitudinally of its axis and has a spherical burnishing surface S located at an angle to its shank and to its axis and this burnishing surface S comprises a pair of spaced portions or annular bands 15 and I6 having a relief surface or groove ll therebetween which allows the metal operated upon by the band l5 or any small particles, to give or slightly flow into this groove which thus acts as a relief surface while the band l6 further burnishes the surface of the work.

This tool is so mounted with relation to the work that the center A of this spherical burnishing surface will approach the spherical surface of the Work to be burnished along the axis of the center line of the work spindle, see Fig. 2.

The burnishing tool holder assembly is rigidly mounted on the tool slide and as the tool slide moves toward the work, the spherical surface S contacts the semi-rough area of the Work creating suflicient contact friction to revolve the burnishing tool about the axis T of the tool. The angular relation D of the burnishing surface S to the axis T causes this surface S to revolve about its axis T and describe the arc B. The limitation of this are B is controlled by the angles C and D.

The contact of the burnishing surfaces on the work at the angle D revolves the burnishing tool faster than at the'angle E and the combination of contact pressureplus therangular revolving of the burnishing tool results in a highly burnished surface.

In practice, the burnishing surface S extends over the edge of the hole I which permits a smooth spherical surface true to form and by reason of the formation of the hole priorto the burnishing operation, the blank is completely formed and burnished prior to its being cut off from the bar so that when out therefrom it is ready for use. 7

It is to be understood that, by describing in detail herein any particular form, structure or arrangement, it is not intended to limit the invention beyond the terms of the several claims or the requirements of the prior art.

Having thus explained the nature of our said invention and described a way of constructing and using the same, although without attempting to set forth all of the forms in which it may be made, or all of the modes of its use, we claim:

1. The method of forming and burnishing a spherically seated blank before it is cut from its stock bar which comprises the operations of rotating the bar in contact with boring and turning instrumentalities to form the blank with a spherical seat, then in contact, with a burnishing instrumentality located at an angle to the stock bar, and then in contact with a cutting-01f instrumentality on the completion of the burnishing operation.

2. The method of forming and burnishing a spherically seated blank before it is cut from its stock bar which comprises the operations of rotating the bar in contact with boring and turning instrumentalities to form the blank with a spherical seat, then in contact with a burnishing instrumentality located at an angle to the stock bar and rotating the same by and with the stock bar, and then in contact with a cutting-off instrumentality on the completion of the burnishing operation.

3. The method of forming and burnishing a spherically seated blank before it is cut from its stock bar which comprises the operations of rotating the bar in contact with boring and turning instrumentalities to form the blank with a spherical seat, then in contact with a burnishing instrumentality having a spherical burnishing surface and so mounted with relation to the work that the center of its spherical burnishing surface will approach the spherical surface of the work along the axis of the center line of the stock bar, and then in contact with a cutting off instrumentality on the completion of the burnishing operation.

4. The method of burnishing a blank prior to its'separation from its stock bar and having a spherical seat therein, which consists in forcing a rotatable burnishing tool having a spherical burnishing surface-into the spherical seat of the blank while on its stock-bar in such manner that the center of its spherical burnishing surface will approach the spherical surface of the work along the axis of the center line of the stock bar, and then subsequently cutting the burnished blank from the bar on,-the completion of the burnishing operation.

5. The method of burnishing a blank prior to its separation from its stock bar and having a spherical seat thereinand an axially bored opening communicating therewith, and which consists in forcing a rotatable burnishing tool having a spherical burnishing surface into the spherical seat of the blank while on its stock bar in such manner that the center of its spherical burnishing surface will approach the spherical surface of the workalong the axis of the center line of the stock bar, and then subsequently cutting the burnished blank from the bar on the completion of the burnishing operation.

6. The method of forming a spherically seated blank which comprises the sequential operations of revolving a stock bar successively in contact with means to form a blank with a spherical seat, then in contact with burnishing means having a spherical surface so that the center of the spherical surface of the burnishing means will approach the spherical surface of the work along the axis of the center line of the work, and then in contact with cutting-off means to sever the burnished'blank from its bar.

7. In a machine of the class described, the combination of a rotary spindle carrying a stock bar, means for forming a blank with a spherical seat from the stock bar, a rotatable burnishing tool having a spherical surface and so mounted that the center of thisspherical surface will approach the work along the axis of the center line of the stock bar, means for forcing said burnishing tool into the spherical seat, and means for cutting off the blank from the stock bar after the seat has been burnished.

8. In a machine of the class described, the combination of a rotary spindle carrying a stock bar, means for forming a blank with a spherical seat from the stock bar, a rotatable burnishing tool having a spherical surface and so mounted that the center of this spherical surface will approach the work along the axis of the center line of the stock bar, meansfor forcing said burnishing tool into the spherical seat, means for cutting oil the blank from the stock bar after the seat has been burnished, and means for r0- tating the bar and tool, one from the other.

9. In a machine of the class described, the combination of a rotary spindle carrying a stock bar, means for forming a blank with a spherical seat from the stock bar; a sliding tool carrier, a rotatable burnishing tool having a spherical surface and so supported on said sliding tool carrier that the center of the spherical surface of the burnishing tool will approach the spherical surface of the work along the axis of the center line of the work, the rotation of the burnishing tool being effected by the rotation of the stock spindle, and means for cutting off the blank from the stock bar after the seat has been burnished.

10. A burnishing tool shaped as a truncated sphere and having a pair of 'angularly located annular bands spaced apart to form a relief groove or recess therebetween and so located that the burnishing surface will approach the work at an angle to the axis thereof.

11. A burnishing tool having a spherical surface having a pair of angularly located spaced burnishing bands and so'located that the burnishing surface will approach the work at an angle to the axis thereof.

12. A burnishing tool having .a spherical surface having a pair of angularly located spaced burnishing bands provided with a relief groove or recess therebetween and so located that the burnishing surface will approach the work at an angle to the axis thereof.

13. A burnishing tool having a burnishing surface located at an angle to the axis of the tool so that the burnishing surface will approach the work at an angle to the axis thereof.

14. A burnishing tool comprising a shank and a burnis-hing surface comprising one or more annular burnishing bands located at an angle to the axis of the tool so that the burnishing surface will approach the work at an angle to the axis thereof.

15. A burnishing tool comprising supporting means and a spherically formed member having. one or more annular burnishing bands located at an angle to the axis of the tool so that the burnishing surface will approach the work at an angle to the axis thereof.

ALFRED E. DRISSNER. ROBERT BEACOM. 

